The efficiency of a gas turbine engine may be improved by raising the gas inlet temperature thereto. Under the present state of the art, gas inlet temperatures are limited by the thermal characteristics of known metals which conventionally are used to form the blades and rotor disk of a gas turbine engine. If cooling of the rotor parts is provided beyond a certain level, the penalties override the gains. As a result, the technology is currently moving in the direction of the use of turbine blades of ceramic materials to replace use of metal in the construction of the turbine blades.
A major problem associated with the use of ceramic turbine blades is the attaching of the blades to a metal rotor disk. The disk itself must be fully protected from exposure to the high temperatures of the incoming gases to the turbine. Moreover, the ceramic blades themselves must be of simple shapes to avoid stress risers therein.
In view of the foregoing problems, a need has arisen for new and improved means for attaching ceramic turbine blades to a rotor disk.